Yes, kinda... There is only one permission problem in my app, my current solution is to switch SELinux to "permissive", do the operation and switch back to "enforcing". This should happen in less than a second. Because of that the rSAP app will need root access again. I'll publish an update today with this change.

Yes. I'm not really happy with this solution, but so far I have no better idea. XDA developer Chainfire (SuperSU) promised to publish a tutorial, how permissions may be added to an existing kernel. But as far as I see it, it might involve patching the kernel image, like his CF-Root tool already does

But there is still the problem of the incompatible radio software on the Nexus 5...